A Novel Analysis of FM Discriminators by Taylor's Expansion

The theory of FM discriminators is presented by expanding its transfer function into Taylor's series, and the application of the results to the typical FM discriminators (slope discriminator, Travis discriminator, Foster-Seeley discriminator, and line discriminator) is added. The output signal of the FM discriminator expressed by Taylor's expansion shows the clear relationship between the fundamental and the harmonics. The design equations obtained from this analysis enable a designer to construct FM discriminators which will provide a desired low distortion performance.